1. Field of the Invention
This invention relates generally to an orthopedic support device for physiological joints, and more specifically to an improved non-rigid orthopedic appliance and method for construction of a flexible orthopedic bracing system designed to limit both rotational and translational motion about the joints of human/animal limbs, especially around joints such as the knee.
2. Description of Related Art
Functional bracing of physiological joints, particularly the human knee joint, is a phenomenon of relatively recent origin. Substantial interest and effort in the bracing of knees in particular arose in the early 1970's, coincident with the origins of "sports medicine". Thus, orthotic bracing systems for various human joints are well known in the art and a wide variety of bracing systems have been developed to address a plethora of conditions for which bracing in some form has been thought to be therapeutically beneficial.
The bracing system in widest use over the last ten to fifteen years may be described as comprising a structural frame made up of a plurality of rigid support components which are linked in a dynamic fashion by one or more mechanical hinges. The frame is generally comprised of two sections, designed to attach to the soft tissue areas proximal and distal to the targeted joint, which are themselves joined by a mechanical hinge of varying design to allow the joint to move within the normal plane of motion. As used herein, "proximal" conventionally refers to a point situated toward the wearer's head while "distal" conventionally refers to a point situated away from the wearer's head. These devices may be described as hinge-post-band or hinge-post-shell devices depending on the configuration of the sections attaching to the soft tissue areas. In such examples, the orthotic can be described as a hard mechanical brace.
Hinged orthopedic bracing devices are commonly employed in an effort to provide stability to a skeletal joint which has been weakened by injury or other infirmity. Braces of this type have been designed primarily to help limit joint separation due to hyperextension or to varus or valgus deformation of the joint. Such devices, as applied to the knee joint, are represented by previously disclosed bracing systems in U.S. Pat. No. 4,503,846 to Martin, U.S. Pat. No. 4,697,583 to Mason et. al., U.S. Pat. No. 4,733,656 to Marquette, U.S. Pat. No. 4,802,466 to Meyers, U.S. Pat. No. 4,941,462 to Lindberg, U.S. Pat. No. 4,986,264 to Miller, U.S. Pat. No. 5,018,514 to Grood, et al., U.S. Pat. No. 5,277,697 to France, et al., U.S. Pat. No. 5,277,698 to Taylor, U.S. Pat. No. 5,336,161 to Lengyel, U.S. Pat. No. 5,433,699 to Smith, U.S. Pat. No. 5,460,599 to Davis, U.S. Pat. No. 5,490,831 to Myers, et al., and U.S. Pat. No. 5,527,268 to Gildersleeve, et al. All of these braces disclose bracing systems comprised of rigid structural elements linked by one or more mechanical hinges. Additional devices of similar construction, having structural elements connected by one or more mechanical hinges, have also been disclosed in U.S. Pat. No. 5,520,627 to Malewicz, as applied to the ankle, and in U.S. Pat. No. 5,437,619 to Malewicz, as applied to the elbow. A derotation brace for the wrist was also disclosed by Malewicz in U.S. Pat. No. 5,520,625.
The brace disclosed by Gildersleeve et al., a current example of the series of braces representing this technology, comprises a hinged orthopedic brace having a frame and one or more pads attached thereto that provide support for the brace when the frame is mounted on the body. This frame is a rigid structure, made up of two sections, one above and one below the joint, dynamically linked together by two hinges on either side of the knee. The frame is mounted onto the body of a user in such a manner that the hinges are positioned to traverse the joint being stabilized. The support frame is attached to the body using a system of pliant bands. This bracing device, like all similarly constructed rigid braces with mechanical hinges, is designed to stabilize the joint by restricting movement to one plane corresponding, in the case of a knee, to normal flexion and extension. Using the knee as the primary example, devices utilizing this current bracing technology are designed to fit around the affected joint in a manner which attempts to limit both hyperextension and lateral movement of the joint. This lateral movement might result from a force applied to the region at or near the lateral or medial condyle aspects of the knee joint, approximately perpendicular to the normal flexion/extension plane of motion in this joint.
Many braces, constructed in the aforementioned manner, have also claimed to attenuate rotational deformations of the knee in addition to lateral and hyperextensive displacements. Among such disclosures are U.S. Pat. No. 4,503,846; U.S. Pat. No. 4,733,656; U.S. Pat. No. 4,802,466; U.S. Pat. No. 4,986,264 and U.S. Pat. No. 5,018,514. All of the aforementioned references which disclose braces claiming to provide such rotational stability are of the hinge-post-band/shell construction. In all such bracing systems, any rotational stability that may be provided is linked to both the medial-lateral and the anterior-posterior stability afforded by the brace. However, rotational stability is not the primary design feature of these braces, but a presumed consequence stemming from that medial-lateral and anterior-posterior stability which the bracing system may provide. Any such stability depends on the ability of the brace to remain stationary with respect to the body after application of the brace and during its use.
In all such rigid, hinged bracing systems, the stability of the brace on the leg is provided by pliant straps which encircle the leg at specific locations. The straps require considerable tightening about the leg to assure that the relatively heavy and rigid devices stay in place about the knee or leg. Even so, the weight of such devices results in the device migrating downwardly on the leg and any rotational stability that might be provided by such devices is lost. In theory, post-hinge-band/shell-type bracing systems claiming to restrict lateral, rotational and/or hyperextensive movement should be of some value in terms of ameliorating the incidence of joint injuries, but that has not been demonstrated biomechanically. The design of these braces is directed to reducing the likelihood of re-injury resulting primarily from medial/lateral and hyperextensive forces rather than those resulting from rotational forces.
While a significant number of injuries occur as a result of lateral and hyperextensive forces on the knee (as well as other joints), it is recognized that a great many joint injuries, especially those involving the anterior cruciate ligament (ACL) of the knee, result from a torsional rotation force about the joint. Current mechanical hinged braces have, as yet, not demonstrated biomechanical efficacy in helping to prevent injuries resulting from such rotational forces.
Other bracing systems have also been disclosed which are less rigid and/or mechanical, such as that disclosed in U.S. Pat. No. 3,680,549 to Lehneis. Still other bracing systems are disclosed which employ soft materials in an effort to provide some support to a joint. Such devices do not, and are not specifically meant to, limit the movement of a joint under stress and, therefore, are not able to fulfill the role of an orthopedic brace. Such devices are disclosed in U.S. Pat. No. 5,399,153 to Caprio, et al., in U.S. Pat. No. 5,407,421 to Goldsmith, in U.S. Pat. No. 5,462,517 to Mann, in U.S. Pat. No. 5,472,413 to Detty and in U.S. Pat. No. 5,474,524 to Carey, among others. Fabric bandages have also been used as joint supports, as disclosed in U.S. Pat. No. 366,590 to Lubin, U.S. Pat. No. 967,585 to Teufel and U.S. Pat. No. 5,385,036 to Spillane, et al. Those devices are stretchably elastic in all directions and thus are designed only to provide a constant, non-variable level of compression about the affected body area. These devices are not designed to limit joint rotation. Indeed, elastic fabric bandages are not effective at preventing joint rotation under physiologically significant loads because of their elasticity in all dimensions. Thus, they cannot accomplish the objectives for which a true bracing system is designed.
Known bracing systems are not specifically designed to effectively constrain axial rotation about a human or animal joint. Thus, it would be advantageous in the art to provide an orthotic device which is specifically designed to provide substantial restriction of axial rotation, as well as translation, about a physiological joint. Further, it would be advantageous to provide such an axial derotation orthotic with the characteristics of being lightweight and flexible, having no rigid structural components or hinged mechanisms, and providing for comfortable, sustained protection while the wearer engages in normal activity.